1. Field of the Invention
The present invention relates to an apparatus for removing a coating film, such as a photoresist, formed on a substrate. More particularly, it relates to an apparatus for removing a coating film around the perimeter of the end surface of a display panel substrate.
2. Description of the Prior Art
As an apparatus for removing a photoresist film around the perimeter of the end surface of a substrate, an apparatus for removing the coating film on a semiconductor wafer in a semiconductor manufacturing process is known. For example, in Japanese Non-examined Patent Publication No. 1-253923, there is employed an EBR (Edge Bead Remover) head using two nozzles ejecting fluid.
In this publication, there is provided an EBR head equipped with a pin type blow nozzle having a nozzle diameter not greater than 1 mm near a pin type chemical rinse nozzle, thereby ejecting a chemical and N2 gas at the same time. Employing this EBR head can prevent a coating film at an interface for removing the coating film from being swelled, so as to reduce lowered quality.
A conventional example 1 shown in FIGS. 10A and 10B applies the above-mentioned structure to a square glass substrate for use in manufacture of a liquid crystal display panel. There is provided with a drive means for moving EBR heads 10 in parallel along the perimeter of a glass substrate 8 formed with a resist film 9, and there is used the EBR head 10 having a plurality of pin type chemical rinse nozzles 17 and pin type blow nozzles 19 aligned thereon, thereby reducing the processing time. This is a conventional example of an apparatus using as a rinse chemical an organic solvent only, such as a thinner in general and is chiefly used for removing a positive photoresist film.
A conventional example 2 shown in FIG. 11 is an example of an apparatus for chiefly continuously processing a negative photoresist film using a chemical rinse and a pure water rinse and adds pin type pure water rinse nozzles 18 to the structure of the conventional example 1. An organic alkaline chemical is often used for this rinse chemical. Which conventional example 1 and 2 is selected depends on the compatibility of a coating film to be removed and the rinse chemical.
In either of the conventional examples 1 and 2, however, use of the pin type nozzles makes it impossible to eject the chemical at high pressure. This is because ejection of the chemical at high pressure will increase force acting inwardly of the substrate accordingly, and it is difficult for the pin type blow nozzle to cover all of the area. Lowering the chemical ejection pressure will weaken a physical force against the substrate surface, reducing the removing efficiency.
In order to thoroughly remove the resist film, it is necessary to reciprocate the EBR head itself several times or to process the film at low speed. Consequently, the processing time is longer and the amount of chemical or gas used is increased. Further, the blow nozzle only suppresses swelling of the removed part interface, and force of the chemical acting on the perimeter of the substrate highly depends on the exhaust ability. The thinner tends to remain on the end surface of the substrate, whereby the coating film component dissolved in the chemical remains on the substrate, adversely affecting the following process.
A conventional example 3 shown in FIG. 12 and a conventional example 4 shown in FIG. 13 are apparatuses using, as a method for removing a coating film, in place of the pin type chemical rinse nozzle, a dip type in which the end of the glass substrate 8 is placed in a rinse liquid 2 in a dip type chemical rinse portion 20. In this method, a new merit capable of linearly, uniformly removing the interface occurs. However, in a manner like the conventional examples 1 and 2, longer processing time is required due to the absence of the physical action, and the edge is likely to rise because the dissolution proceeds isotropically.
As described above, in the conventional examples 1 and 2, the processing time is longer and the amount of the chemical or gas used is increased. Further, in the conventional examples 3 and 4, in a manner like the conventional examples 1 and 2, longer processing time is required due to the absence of the physical action, and the edge is likely to rise because the dissolution proceeds isotropically.
These problems can be reduced to a usable level by adjusting a chemical used, processing time, the operation of the EBR itself, sequence, exhaust conditions and the like, but the problem that the process margin is small still remains.
An object of the present invention is to provide an apparatus for removing a coating film which meets an ability of uniformly removing the coating film and can remove the coating film fast.
A further object of the present invention, in addition to the above object, is to provide an apparatus for removing a coating film in which the amount of a chemical used is small, no liquid remains after processing, and a process margin is large.
According to the present invention, there is provided an apparatus for removing a coating film comprising a chemical rinse nozzle having an opening ejecting a chemical dissolving a coating film around the perimeter of the end surface of a substrate formed with the coating film, and a slit type blow nozzle having a slit opening ejecting gas to the substrate so as to remove the coating film dissolved by the chemical from the substrate.
The chemical rinse nozzle comprises a slit type chemical rinse nozzle having an opening in slit form. In the apparatus for removing a coating film provided with the slit type chemical rinse nozzle, the slit type chemical rinse nozzle is arranged between the slit type blow nozzle and the end of the substrate.
In such an apparatus for removing a coating film, the slit type blow nozzle and the slit type chemical rinse nozzle have a slit opening extending along one side of the substrate, respectively, the length of each opening being longer than one side of the substrate.
The slit type chemical rinse nozzle and the slit type blow nozzle may be of integrated nozzle construction, and the opening of the integrated nozzle construction may be single.
Furthermore, the apparatus for removing a coating film comprises a slit type pure water rinse nozzle having a slit opening ejecting pure water between the slit type blow nozzle and the slit type chemical rinse nozzle. The integration of the slit type pure water rinse nozzle and the slit type blow nozzle comprises a slit opening ejecting a mixture of the gas and the pure water.
The apparatus for removing a coating film according to the present invention comprises the first nozzle unit constructed by a combination of the slit type chemical rinse nozzle and the slit type blow nozzle, the second nozzle unit constructed by a combination of a slit type pure water rinse nozzle disposed adjacent to the slit type chemical rinse nozzle and having a slit opening ejecting pure water and the second slit type blow nozzle disposed adjacent to the slit type blow nozzle and having a slit opening ejecting gas, the first nozzle unit and the second nozzle unit being disposed adjacent each other along one side of the substrate, and carry means for carrying the substrate from the first nozzle unit to the second nozzle unit.
Such an apparatus for removing a coating film further comprises the third and the fourth nozzle units having the same construction as that of the first and the second nozzle units, the first and the third nozzle units being disposed to interpose one side of the substrate, and the second and the fourth nozzle units being disposed to interpose one side of the substrate.
The integration of the slit type chemical rinse nozzle and the slit type blow nozzle by being separated by a common partition comprises a slit type chemical rinse and blow nozzle provided with a slit opening ejecting the gas and the chemical independently.
The integration of the slit type pure water rinse nozzle and the slit type blow nozzle by being separated by a common partition comprises a slit type pure water rinse and blow nozzle provided with a slit opening ejecting the gas and the pure water independently.
A nozzle unit comprising the slit type chemical rinse and blow nozzle, and the slit type pure water rinse and blow nozzle is disposed so as to interpose one side of the substrate to be carried.